tests: Use pytest-warnings to handle warnings

misc/requirements/requirements-tests.txt

@@ -26,6 +26,7 @@ pytest-qt==1.11.0
 pytest-repeat==0.3.0
 pytest-rerunfailures==2.0.0
 pytest-travis-fold==1.2.0
+pytest-warnings==0.1.0
 pytest-xvfb==0.2.0
 six==1.10.0
 vulture==0.10

misc/requirements/requirements-tests.txt-raw

@@ -15,6 +15,7 @@ pytest-qt
 pytest-repeat
 pytest-rerunfailures
 pytest-travis-fold
+pytest-warnings
 pytest-xvfb
 vulture
 

pytest.ini

@@ -1,5 +1,5 @@
 [pytest]
-addopts = --strict -rfEw --faulthandler-timeout=70 --instafail
+addopts = --strict -rfEw --faulthandler-timeout=70 --instafail --pythonwarnings error
 markers =
     gui: Tests using the GUI (e.g. spawning widgets)
     posix: Tests which only can run on a POSIX OS.

tests/conftest.py

@@ -133,13 +133,6 @@ def qapp(qapp):
     return qapp
 
 
-@pytest.yield_fixture(autouse=True)
-def fail_tests_on_warnings():
-    warnings.simplefilter('error')
-    yield
-    warnings.resetwarnings()
-
-
 def pytest_addoption(parser):
     parser.addoption('--qute-delay', action='store', default=0, type=int,
                      help="Delay between qutebrowser commands.")